Emulsifying agent and method of preparing same



Patented Aug. 9, 1938 UNITED STATES PATENT OFFICE EMULSIFYING AGENT AND METHOD OF PREPARING SAME ware No Drawing. Application May 11, 1934, Serial No. 725,086

12 Claims.

This invention relates to a novel emulsifying agent and method of preparing same and the present application is a continuation in part of application Serial No. 372,529 filed June 20, 1929, now U. S. Patent 2,061,601 in which an emulsifying composition was disclosed which comprised essentially a mixture of an alcohol amine soap of oil-soluble sulfonic acids derived from petroleum with petroleum oil-soluble sulfonic acid com- 10 pound or salt thereof.

An example of the composition claimed originally is a mixture of triethanolamine sulfonate soap with a sodium salt of oil-soluble sulfonic acid, the sulfonic radicals from both soaps being 15 obtained from the same fraction or different fractions of petroleum lubricatingoil stock such as i used in making the heavy mineral white oil marketed under the name Nujol. In the original application it was pointed out specifically that the admixture of oil-soluble sulfonates increased the solubility of the alcohol amine soaps in oil and thereby improved the emulsifying capacity of said alcohol amine sulfonatea- The amount'of oilsoluble sulfonates to be used may vary'over fairly wide limits, such as from one-half to three parts of oil-soluble sulfonate to one part of alcohol amine soap, depending upon the purity of the soaps and the type of oil being used.

It has also been discovered and is theprimary feature of the present invention that the addition of relatively small amounts of alcohol amine soaps to oil-soluble sulfonates causes an unexpected improvement in emulsifying properties of the latter. It is recognized in the art that highly purified oil-soluble sulfonates may possess good emulsifying characteristics but that small amounts of impurities of various sorts, such as oily constituents, inorganic salts, etc. which may be present in crude oil-soluble sulfonates, prior .0 toany purification, may markedly decrease the emulsifying capacity of said oil-soluble sulfonates.

One embodiment of the present invention is the addition of a small amount of alcohol amine soaps of petroleum sulfonic acids, oleic acid,

5 stearic acid, naphthenic acids, etc. to relatively crude oil-soluble sulfonates having poor emulsifying characteristics. in order to impart good emulsifying properties thereto. However, the invention is not limited to the use of crude oilsoluble sulfonates because it has been found that even highly refined oil-soluble sulfonates having good emulsifying properties may be still further improved by the addition of small amounts of 55 alcohol amine soaps.

The invention will be fully understood from the following description:

It is an old practice in the refining of oils to treat the oil with strong sulfuric acid. Such treatment is usual in the refining of lubricating oils, in the preparation of the so-called white oils, etc. The strong sulfuric acid causes sulfonation of certain hydrocarbons. These sulfonic acids derived from petroleum are partly soluble in the oil, partly insoluble. The former remain 1 dissolved in the petroleum oil while the latter are found in the sludge. The acid oil containing oilsoluble sulfonic acids is then neutralized with ethanolamine or with some other alcohol amine as claimed in the parent application referred to. The ethanolamine is obtainable on the market in the form of a glycerine-lik'e viscous liquid and usually consists of a mixture of mono-, di-, and' triethanolamine. Other alcoholamines may be used in this process such as, for instance, propanolamines, etc. The neutralization is carried out by adding the amine to the oil in small quantities at a time until the oil shows a slightly alkaamine is added. The oil is then allowed to settle,

preferably over night. The bulk of the ethanol.- amine soaps formed-with the sulfonic acids separates out and the rest may be washed out with water or with some organic solvent such as isopropyl alcohol, etc.

The amount of alcohol amine necessary for the neutralization depends on the nature of the amine employed, and the percentage of sulfonic acids present in the acid oil, and may vary within wide limits. However, this amount can be easily deter- 40 mined in each case since it is necesary to determine only the point when the reaction of the oil becomes alkaline.

Alcohol amines may also be used for the neutralization of the water-soluble sulfonic acids of r the sludge mentioned above. The procedure is analogous to the neutralization of the acid oils as just described.

The structural formula of the triethanolamine sulfonic acid soap is probably the following:

they are obtained from an oil of about 225-250 Saybolt viscosity at 100 F., or they may be like a thick syrupy liquid when obtained from an oil of 80-100 viscosity. The color of these soaps depends on the degree of purification of the oil previous to precipitating out of the sulfonic acids in form of the soaps, and it may vary from light amber to dark red.

These sulfonic acid soaps of the alcohol amines are good emulsifying agents for oil-in-water type emulsions, but these soaps are relatively expensive and, therefore, cannot be used to a great extent commercially by themselves. However, according to the present invention, small amounts of these alcohol amine soaps are added to oil-soluble sulfonate soaps which are relatively much cheaper, in order to increase the emulsifying properties of the latter. For example, about 10% of ethanolamine sulfonates such as prepared above is added to a batch of oil-soluble sulfonates having relatively poor emulsifying characteristics (whether the poor quality is due to the presence of impurities or due to the nature of the petroleum stock from which it was made). Mixtures of a major proportion, i. e. over 50%, of oil-soluble sulfonate soaps and a minor proportion, 1. e. less than 50%, of alcohol amine soaps of relatively high molecular weight organic acids may be used, though preferably the mixtures are ones containing from 0.5% to 20.0% of an alcohol amine soap. When added to Nujol,

which is a commercial white oil, the latter formed an emulsion on shaking with water. Oil containing 1% or 2% of this mixture formed emulsions of the quick breaking type while an oil containing 4% or more of the mixture formed stable emulsions.

The oil-soluble sulfonates used may be prepared according to any of the well known methods and they may be used either in a cheaper crude form or in a purified form. Generally, oil is treated with sulfuric acid and the resulting acid sludge is removed, then the remaining acid oil is neutralized with soda and the resulting sulfonates are extracted from the oil by an aqueous alcoholic solution from which the sulfonates, in more or less crude form, are obtained by evaporation. One particular method of preparing purified oil-soluble sulfonates comprises isolating them directly from the aqueous alcoholic solution by agitating the latter with alkali carbonates, drawing off and filtering the upper layer and evaporating the filtrate to dryness. In preparing these oil-soluble sulfonates, one may use either alkalies such as caustic soda or potash or alkaline earth hydroxides, such as lime or magnesia, or various other bases. The iron and manganese sulfonates may be used.

Instead of preparing the alcohol amine sulfonate soaps as described hereinabove by direct neutralization of acid oil with an alcohol amine, they may be prepared by simple admixture of an alcohol amine with sulfonic acids reconstituted from the sodium or other salts thereof, as by treatment with sulfuric acid. The alcohol amine sulfonate soaps may be prepared either from oilsoluble sulfonic acids or from water-soluble sulfonic acids extracted, according to known methods, from the acid sludge resulting from the treatment of petroleum stocks with strong sulfuric acid. Also, the alcohol amine soaps may be prepared by the use of other types of acids such as oleic acid, stearic acid, naphthenic acids, benzoic acid, etc. By the term alcohol amine is intended to be included the mono-, di-, or trialkylol or arylol amines such as diethanolamine, monomethanol diethanolamine, dimethyl monomethanolamine, diphenylamine, etc. Also higher molecular weight amines containing about 5 to 20 carbon atoms or so, such as may be prepared from chlorhydrins of olefines or cracked wax, or from ehlor fatty hydroxy acids, etc., may be used.

An example of the use of an alcohol amine oleate is as follows:

To a sample of mineral white oil is added 7% of oil-soluble sulfonates (derived from a petroleum lubricating oil stock used for preparing Nujol, said sulfonates being purified by the particular method described hereinabove) and 1 /2% of triethanolamine oleate. This composition was found to be at least equivalent to a similar oil containing 14% of the same oil-soluble sulfonates but containing no triethanolamine oleate. In other words, 1 of triethanolamine oleate was at least equivalent to 7% of the oil-soluble sulfonate. and also the mixture was superior to either constituent alone. It is therefore, apparent that some new and unexpected results have been obtained.

It is not intended that the invention be limited by any of the examples given nor by any theories suggested for the operation of the invention but only by the appended claims in which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

1. A new composition comprising a major proportion of oil-soluble sulfonates derived from petroleum and a minor proportion of alcohol amine soap.

2. A composition according to claim 1, in which the oil-soluble sulfonates are salts of a metal of the group consisting of alkalies, alkaline earths; iron and manganese.

3. An emulsifying agent comprising a major proportion of oil-soluble sulfonate derived from petroleum and approximately 0.5 to 20% of an alcohol amine soap of a relatively high molecular weight organic acid.

4. An emulsifying agent comprising a major proportion of oil-soluble sulfonates derived from petroleum and a minor proportion of an alcohol amine sulfonate derived from petroleum.

5. An emulsifying agent comprising a major proportion of oil-soluble sulfonate derived from petroleum and a minor proportion of triethanolamine sulfonate.

6. An emulsifying agent comprising a major proportion of crude oil-soluble sulfonates derived from petroleum and a small amount of an alcohol amine soap.

7. An emulsifying agent comprising a major proportion of purified oil-soluble sulfonates derived from petroleum and a small amount of an alcohol amine soap adapted to improve the emulsifying characteristics of the composition.

8. An emulsifiable composition comprising a major quantity of an oil of the group consisting of animal, vegetable, mineral lubricating oils and mineral white oils, a minor proportion of an oilsoluble sulfonate soap derived from petroleum and a small amount of an alcohol amine soap adapted to increase the emulsifying properties of the oil-soluble sulfonate soap.

9. The method of improving the emulsifying properties of oil-soluble sulfonates derived from petroleum which comprises adding thereto a small amount of an alcohol amine soap derived by neutralizing an acid-treated petroleum oil with an alcohol amine.

10. The method of preparing a composition having valuable emulsifying properties which comprises adding 0.5-6! parts of an alcohol amine soap, derived by neutralizing an acidtreated petroleum-oil with an alcohol amine, to an amount of oil-soluble sulfonates, derived from petroleum, suflicient to make a total of 100 parts of the composition, whereby the emulsifying capacity of the composition is superior to that of 10 100 parts of either component taken separately.

11. The method of improving the emulsifying properties of an alcohol amine soap derived by neutralizing an acid-treated petroleum oil with an alcohol amine, which comprises adding onehalf to three parts of oil-soluble sulfonates derived from petroleum to one part of said soap. 12. An emulsion comprising essentially oil and water, and, in addition, a minor proportion of an emulsifying agent comprising a composition as defined in claim 1.

KARL T. STEIK.

STEWART C. FULTON. 

